The phenotypic ratio in F₂ of a dihybrid cross is:

1. In a dihybrid cross two pairs of contrasting characters are followed at once. 2. Mendel crossed round-yellow seeded plants with wrinkled-green ones. 3. The F₁ generation was all round-yellow (both dominant). 4. F₂ self-cross gave four phenotype groups in the ratio 9:3:3:1. 5. So the F₂ phenotypic ratio in a dihybrid cross is 9:3:3:1. _Source: NCERT Class 10 Science Ch 9 'Heredity' (learncbse.in extract)_